Molecular-beam epitaxy and characteristics of GaNyAs1−x−yBix

Ga N y As 1 − x − y Bi x alloys were grown by molecular-beam epitaxy using solid Ga, Bi, and As sources and nitrogen radicals generated from nitrogen gas in rf plasma. Changing the growth temperature is found to be a convenient method for controlling the GaBi molar fraction in the alloy reproducibly. The photoluminescence (PL) spectra show that the PL peak energy of GaNyAs1−x−yBix alloy decreased with increasing GaBi and GaN molar fractions. The redshift coefficients of ∼62meV∕%Bi and ∼130meV∕%N at the PL peak energy of GaNyAs1−x−yBix were observed at room temperature. The temperature dependence of the PL peak energy in the temperature range of 150–300K is much smaller than the temperature dependence of the band gap of InGaAsP. The temperature coefficients of GaAs1−xBix and GaNyAs1−x−yBix band gaps are governed by the GaBi molar fraction and they decrease with increasing GaBi molar fraction. GaNyAs1−x−yBix alloys with different PL peak energies and lattice matched to GaAs substrates were obtained. The photoluminescence peak energy was located at a predicted wavelength for the sample lattice matched to GaAs which was found to have the structure of Ga(N0.33Bi0.67)zAs1−z.